1. Field of the Invention
The invention relates generally to manufacture of flexible materials for packaging and the like. More particularly, it relates to a method for manufacturing permeable films.
2. Background Information
In the packaging industry, allowing oxygen to permeate a film or package so as to contact a product contained therein often is desired. For example, a package utilizing a permeable film can permit oxygen to permeate to a fresh red meat product in the package, thereby allowing the meat product to oxygenate (sometimes called blooming). This can enhance consumer appeal, and retail vendors of such meat products have begun to demand this type of capability. Additionally, many types of produce require the presence of oxygen to suppress anaerobic spoilage.
To obtain sufficient permeability, films frequently are treated with mechanical perforating mechanisms. Unfortunately, mechanical perforation is expensive and cannot be accomplished easily after film manufacture or packaging by, for example, retail vendors. Furthermore, providing perforations which are sufficiently small and uniform in size is a not insubstantial challenge using presently available mechanical perforating techniques.
The need remains for an efficient, cost-effective, versatile method of making permeable films.